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- /*
- * jcinit.c
- *
- * Copyright (C) 1991-1997, Thomas G. Lane.
- * Modified 2003-2017 by Guido Vollbeding.
- * This file is part of the Independent JPEG Group's software.
- * For conditions of distribution and use, see the accompanying README file.
- *
- * This file contains initialization logic for the JPEG compressor.
- * This routine is in charge of selecting the modules to be executed and
- * making an initialization call to each one.
- *
- * Logically, this code belongs in jcmaster.c. It's split out because
- * linking this routine implies linking the entire compression library.
- * For a transcoding-only application, we want to be able to use jcmaster.c
- * without linking in the whole library.
- */
- #define JPEG_INTERNALS
- #include "jinclude.h"
- #include "jpeglib.h"
- /*
- * Compute JPEG image dimensions and related values.
- * NOTE: this is exported for possible use by application.
- * Hence it mustn't do anything that can't be done twice.
- */
- GLOBAL(void)
- jpeg_calc_jpeg_dimensions (j_compress_ptr cinfo)
- /* Do computations that are needed before master selection phase */
- {
- /* Sanity check on input image dimensions to prevent overflow in
- * following calculations.
- * We do check jpeg_width and jpeg_height in initial_setup in jcmaster.c,
- * but image_width and image_height can come from arbitrary data,
- * and we need some space for multiplication by block_size.
- */
- if (((long) cinfo->image_width >> 24) || ((long) cinfo->image_height >> 24))
- ERREXIT1(cinfo, JERR_IMAGE_TOO_BIG, (unsigned int) JPEG_MAX_DIMENSION);
- #ifdef DCT_SCALING_SUPPORTED
- /* Compute actual JPEG image dimensions and DCT scaling choices. */
- if (cinfo->scale_num >= cinfo->scale_denom * cinfo->block_size) {
- /* Provide block_size/1 scaling */
- cinfo->jpeg_width = cinfo->image_width * cinfo->block_size;
- cinfo->jpeg_height = cinfo->image_height * cinfo->block_size;
- cinfo->min_DCT_h_scaled_size = 1;
- cinfo->min_DCT_v_scaled_size = 1;
- } else if (cinfo->scale_num * 2 >= cinfo->scale_denom * cinfo->block_size) {
- /* Provide block_size/2 scaling */
- cinfo->jpeg_width = (JDIMENSION)
- jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 2L);
- cinfo->jpeg_height = (JDIMENSION)
- jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 2L);
- cinfo->min_DCT_h_scaled_size = 2;
- cinfo->min_DCT_v_scaled_size = 2;
- } else if (cinfo->scale_num * 3 >= cinfo->scale_denom * cinfo->block_size) {
- /* Provide block_size/3 scaling */
- cinfo->jpeg_width = (JDIMENSION)
- jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 3L);
- cinfo->jpeg_height = (JDIMENSION)
- jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 3L);
- cinfo->min_DCT_h_scaled_size = 3;
- cinfo->min_DCT_v_scaled_size = 3;
- } else if (cinfo->scale_num * 4 >= cinfo->scale_denom * cinfo->block_size) {
- /* Provide block_size/4 scaling */
- cinfo->jpeg_width = (JDIMENSION)
- jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 4L);
- cinfo->jpeg_height = (JDIMENSION)
- jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 4L);
- cinfo->min_DCT_h_scaled_size = 4;
- cinfo->min_DCT_v_scaled_size = 4;
- } else if (cinfo->scale_num * 5 >= cinfo->scale_denom * cinfo->block_size) {
- /* Provide block_size/5 scaling */
- cinfo->jpeg_width = (JDIMENSION)
- jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 5L);
- cinfo->jpeg_height = (JDIMENSION)
- jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 5L);
- cinfo->min_DCT_h_scaled_size = 5;
- cinfo->min_DCT_v_scaled_size = 5;
- } else if (cinfo->scale_num * 6 >= cinfo->scale_denom * cinfo->block_size) {
- /* Provide block_size/6 scaling */
- cinfo->jpeg_width = (JDIMENSION)
- jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 6L);
- cinfo->jpeg_height = (JDIMENSION)
- jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 6L);
- cinfo->min_DCT_h_scaled_size = 6;
- cinfo->min_DCT_v_scaled_size = 6;
- } else if (cinfo->scale_num * 7 >= cinfo->scale_denom * cinfo->block_size) {
- /* Provide block_size/7 scaling */
- cinfo->jpeg_width = (JDIMENSION)
- jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 7L);
- cinfo->jpeg_height = (JDIMENSION)
- jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 7L);
- cinfo->min_DCT_h_scaled_size = 7;
- cinfo->min_DCT_v_scaled_size = 7;
- } else if (cinfo->scale_num * 8 >= cinfo->scale_denom * cinfo->block_size) {
- /* Provide block_size/8 scaling */
- cinfo->jpeg_width = (JDIMENSION)
- jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 8L);
- cinfo->jpeg_height = (JDIMENSION)
- jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 8L);
- cinfo->min_DCT_h_scaled_size = 8;
- cinfo->min_DCT_v_scaled_size = 8;
- } else if (cinfo->scale_num * 9 >= cinfo->scale_denom * cinfo->block_size) {
- /* Provide block_size/9 scaling */
- cinfo->jpeg_width = (JDIMENSION)
- jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 9L);
- cinfo->jpeg_height = (JDIMENSION)
- jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 9L);
- cinfo->min_DCT_h_scaled_size = 9;
- cinfo->min_DCT_v_scaled_size = 9;
- } else if (cinfo->scale_num * 10 >= cinfo->scale_denom * cinfo->block_size) {
- /* Provide block_size/10 scaling */
- cinfo->jpeg_width = (JDIMENSION)
- jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 10L);
- cinfo->jpeg_height = (JDIMENSION)
- jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 10L);
- cinfo->min_DCT_h_scaled_size = 10;
- cinfo->min_DCT_v_scaled_size = 10;
- } else if (cinfo->scale_num * 11 >= cinfo->scale_denom * cinfo->block_size) {
- /* Provide block_size/11 scaling */
- cinfo->jpeg_width = (JDIMENSION)
- jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 11L);
- cinfo->jpeg_height = (JDIMENSION)
- jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 11L);
- cinfo->min_DCT_h_scaled_size = 11;
- cinfo->min_DCT_v_scaled_size = 11;
- } else if (cinfo->scale_num * 12 >= cinfo->scale_denom * cinfo->block_size) {
- /* Provide block_size/12 scaling */
- cinfo->jpeg_width = (JDIMENSION)
- jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 12L);
- cinfo->jpeg_height = (JDIMENSION)
- jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 12L);
- cinfo->min_DCT_h_scaled_size = 12;
- cinfo->min_DCT_v_scaled_size = 12;
- } else if (cinfo->scale_num * 13 >= cinfo->scale_denom * cinfo->block_size) {
- /* Provide block_size/13 scaling */
- cinfo->jpeg_width = (JDIMENSION)
- jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 13L);
- cinfo->jpeg_height = (JDIMENSION)
- jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 13L);
- cinfo->min_DCT_h_scaled_size = 13;
- cinfo->min_DCT_v_scaled_size = 13;
- } else if (cinfo->scale_num * 14 >= cinfo->scale_denom * cinfo->block_size) {
- /* Provide block_size/14 scaling */
- cinfo->jpeg_width = (JDIMENSION)
- jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 14L);
- cinfo->jpeg_height = (JDIMENSION)
- jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 14L);
- cinfo->min_DCT_h_scaled_size = 14;
- cinfo->min_DCT_v_scaled_size = 14;
- } else if (cinfo->scale_num * 15 >= cinfo->scale_denom * cinfo->block_size) {
- /* Provide block_size/15 scaling */
- cinfo->jpeg_width = (JDIMENSION)
- jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 15L);
- cinfo->jpeg_height = (JDIMENSION)
- jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 15L);
- cinfo->min_DCT_h_scaled_size = 15;
- cinfo->min_DCT_v_scaled_size = 15;
- } else {
- /* Provide block_size/16 scaling */
- cinfo->jpeg_width = (JDIMENSION)
- jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 16L);
- cinfo->jpeg_height = (JDIMENSION)
- jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 16L);
- cinfo->min_DCT_h_scaled_size = 16;
- cinfo->min_DCT_v_scaled_size = 16;
- }
- #else /* !DCT_SCALING_SUPPORTED */
- /* Hardwire it to "no scaling" */
- cinfo->jpeg_width = cinfo->image_width;
- cinfo->jpeg_height = cinfo->image_height;
- cinfo->min_DCT_h_scaled_size = DCTSIZE;
- cinfo->min_DCT_v_scaled_size = DCTSIZE;
- #endif /* DCT_SCALING_SUPPORTED */
- }
- /*
- * Master selection of compression modules.
- * This is done once at the start of processing an image. We determine
- * which modules will be used and give them appropriate initialization calls.
- */
- GLOBAL(void)
- jinit_compress_master (j_compress_ptr cinfo)
- {
- long samplesperrow;
- JDIMENSION jd_samplesperrow;
- /* For now, precision must match compiled-in value... */
- if (cinfo->data_precision != BITS_IN_JSAMPLE)
- ERREXIT1(cinfo, JERR_BAD_PRECISION, cinfo->data_precision);
- /* Sanity check on input image dimensions */
- if (cinfo->image_height <= 0 || cinfo->image_width <= 0 ||
- cinfo->input_components <= 0)
- ERREXIT(cinfo, JERR_EMPTY_IMAGE);
- /* Width of an input scanline must be representable as JDIMENSION. */
- samplesperrow = (long) cinfo->image_width * (long) cinfo->input_components;
- jd_samplesperrow = (JDIMENSION) samplesperrow;
- if ((long) jd_samplesperrow != samplesperrow)
- ERREXIT(cinfo, JERR_WIDTH_OVERFLOW);
- /* Compute JPEG image dimensions and related values. */
- jpeg_calc_jpeg_dimensions(cinfo);
- /* Initialize master control (includes parameter checking/processing) */
- jinit_c_master_control(cinfo, FALSE /* full compression */);
- /* Preprocessing */
- if (! cinfo->raw_data_in) {
- jinit_color_converter(cinfo);
- jinit_downsampler(cinfo);
- jinit_c_prep_controller(cinfo, FALSE /* never need full buffer here */);
- }
- /* Forward DCT */
- jinit_forward_dct(cinfo);
- /* Entropy encoding: either Huffman or arithmetic coding. */
- if (cinfo->arith_code)
- jinit_arith_encoder(cinfo);
- else {
- jinit_huff_encoder(cinfo);
- }
- /* Need a full-image coefficient buffer in any multi-pass mode. */
- jinit_c_coef_controller(cinfo,
- (boolean) (cinfo->num_scans > 1 || cinfo->optimize_coding));
- jinit_c_main_controller(cinfo, FALSE /* never need full buffer here */);
- jinit_marker_writer(cinfo);
- /* We can now tell the memory manager to allocate virtual arrays. */
- (*cinfo->mem->realize_virt_arrays) ((j_common_ptr) cinfo);
- /* Write the datastream header (SOI) immediately.
- * Frame and scan headers are postponed till later.
- * This lets application insert special markers after the SOI.
- */
- (*cinfo->marker->write_file_header) (cinfo);
- }
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